近日，南京大学现代工程与应用科学学院的夏可宇&陆延青及其研究小组与湖南师范大学物理与电子科学学院的景辉等人合作并取得一项新进展。经过不懈努力，他们成功观察到损耗增强磁光效应。相关研究成果已于2024年12月19日在国际知名学术期刊《自然—光子学》上发表。
本研究介绍了一种损耗增强的磁光（MO）效应，用于在不同背景磁场下亚线性地放大非厄米光学腔的频率响应。这种特殊的磁光效应依赖于嵌入法布里-珀罗（Fabry-Pérot）腔中的磁光材料结构，同时结合偏振依赖的光吸收（即线性二色性）来构建一个可重构的奇异点。
实验结果表明，法布里-珀罗腔的两个本征模表现出亚线性频率分裂。通过电学方式重新配置吸收体，可以在不同背景磁场下自适应地增强本征频率偏移。利用这一效应，研究人员实现了在强背景磁场中检测微弱磁场变化，与传统的厄米系统相比，系统响应放大了10倍以上，灵敏度提高了三倍。本研究利用奇异物理来研究磁光效应，并开发了一类具有增强灵敏度的新型可重构磁光器件，有望与光子系统集成。
据悉，磁光（MO）效应在现代用于光操纵和传感的光子器件中发挥着核心作用，但迄今为止，对这些效应的研究仅限于磁光法拉第效应和克尔效应。传统的磁光系统存在显著的固有损耗，严重阻碍了它们增强磁光效应的能力。
附：英文原文
Title: Observation of loss-enhanced magneto-optical effect
Author: Ruan, Ya-Ping, Tang, Jiang-Shan, Li, Zhipeng, Wu, Haodong, Zhou, Wenpeng, Xiao, Longqi, Chen, Jianfeng, Ge, Shi-Jun, Hu, Wei, Zhang, Han, Qiu, Cheng-Wei, Liu, Wuming, Jing, Hui, Lu, Yan-Qing, Xia, Keyu
Issue&Volume: 2024-12-19
Abstract: Magneto-optical (MO) effects have a pivotal role in modern photonic devices for light manipulation and sensing, but the study of these effects has so far been limited to the MO Faraday and Kerr effects. Conventional MO systems encounter considerable intrinsic losses, markedly hampering their ability to amplify the MO effects. Here we introduce a loss-enhanced MO effect to sublinearly amplify the frequency response of a non-Hermitian optical cavity under different background magnetic fields. This exceptional MO effect relies on an architecture of MO material embedded in a Fabry–Pérot cavity, accompanied by a polarization-dependent optical absorption, that is, linear dichroism, to construct a reconfigurable exceptional point. The experimental results show that two eigenmodes of the Fabry–Pérot cavity exhibit sublinear frequency splitting. By electrically reconfiguring the absorber, the eigenfrequency shift can be adaptively enhanced under different background magnetic fields. Using this effect, we demonstrate the detection of subtle magnetic field variations in a strong background, with the system’s response magnified by a factor exceeding 10 and sensitivity increased threefold compared with its conventional Hermitian counterpart. Our study leverages exceptional physics to study the MO effect and develops a new class of reconfigurable MO devices equipped with enhanced sensitivity for potential integration with photonic systems.
DOI: 10.1038/s41566-024-01592-y
Source: https://www.nature.com/articles/s41566-024-01592-y